When using a packet data service, a mobile user in a 3rd Generation Partnership Project (3rd Generation Partnership Project, 3GPP) network usually uses data transmission functions of a transmission control protocol (Transmission Control Protocol, TCP) and a radio link control (Radio Link Control, RLC) protocol simultaneously.
During service data transmission, a TCP data packet sent by a TCP transmit end is forwarded to a user equipment using a radio access network (Radio Access Network, RAN) device, and the user equipment returns a TCP acknowledgement (ACK) message to an RNC device. Because the TCP data packet is encapsulated in an RLC link into multiple RLC acknowledged mode data protocol data unit(s) (Acknowledged Mode Data Protocol Data Unit, AMD PDU) and then transmitted to the user equipment, the user equipment needs to send an RLC protocol status report (status report) to the user equipment to notify the RNC device that the user equipment has successfully received the RLC protocol AMD PDUs. That is to say, during service data transmission, a large number of TCP ACK and RLC status report data transmission acknowledgements are generated on the user equipment, where the data transmission acknowledgements include duplicate acknowledgements, seriously wasting precious air interface bandwidth and frequency resources.